text: Tetrahedral Tanabe–Sugano diagrams are generally not found in textbooks because the diagram for a d tetrahedral will be similar to that for d octahedral, remembering that Δ for tetrahedral complexes is approximately 4/9 of Δ for an octahedral complex.  A consequence of the much smaller size of Δ results in (almost) all tetrahedral complexes being high spin and therefore the change in the ground state term seen on the X-axis for octahedral d-d diagrams is not required for interpreting spectra of tetrahedral complexes.